Fuel pump

Abstract

A fuel pump has a motor portion and a pump portion, wherein fuel is sucked from an inlet port into the pump portion when an impeller is rotated and the pressurized fuel is discharged out of the fuel pump from an outlet port. A stator has multiple stator cores on which respective stator coils are wound to form a star-connection winding. A terminal sub-assembly is provided hi an axial side portion of the stator. The terminal sub-assembly has multiple conductive members and each end portion of the stator coils is respectively connected to connecting portions of the conductive members, which are arranged at equal intervals in a circumferential direction of the terminal sub-assembly.

What is claimed is: 
     
       1. A fuel pump comprising: a cylindrical housing; a pump cover for closing one end of the housing and having an inlet port; an end cover for closing the other end of the housing and having an outlet port; a cylindrical stator having multiple stator cores, on each of which stator coils corresponding to respective phase windings is wound, the multiple stator cores being arranged at an inner peripheral surface of the housing and in a circumferential direction of the housing, wherein each of the stator coils are composed of multiple pairs of coils which are opposed to each other with respect to a center axis of the cylindrical stator and the coils of each pair form the same phase winding;
 a rotor rotatably accommodated in an inside of the stator in a radial direction thereof; a shaft coaxially arranged with the rotor so that the shaft is rotated together with the rotor; 
 an impeller connected to the shaft and thereby rotated together with the shaft so as to draw fuel from the inlet port and to pump out pressurized fuel from the outlet port; and 
 a terminal sub-assembly provided in an axial side portion of the stator on a side of the end cover, 
 wherein the terminal sub-assembly has multiple conductive members connected to end portions of the stator coils on the side of the end cover, 
 wherein the multiple conductive members are integrally formed in the terminal sub-assembly, and 
 wherein the terminal sub-assembly has terminals, to which wires are connected to supply electric power to the stator coils, 
 wherein each of the conductive members is formed in an arc shape, 
 wherein each of the terminals extends in a direction parallel to the center axis of the cylindrical stator, 
 wherein each of the conductive members is arranged in a circumferential direction of the terminal sub-assembly and displaced by a predetermined angle from one another in the circumferential direction, 
 wherein the conductive members are integrally molded with resin, and 
 wherein each of the terminals is arranged in a straight line and a part of each of the terminals is molded with the resin. 
 
     
     
       2. The fuel pump according to  claim 1 , further comprising:
 a pressure relief valve, which is opened when pressure of the fuel in a space surrounded by the housing, the pump cover and the end cover exceeds a predetermined value, wherein the terminal sub-assembly is formed in a C-letter shape, and wherein the pressure relief valve is provided at a position which is located in an open area of the C-letter shaped terminal sub-assembly. 
 
     
     
       3. The fuel pump according to  claim 2 , wherein the outlet port is provided at a position which is located in an inner peripheral area of the C-letter shaped terminal sub-assembly. 
     
     
       4. The fuel pump according to  claim 1 , wherein the conductive members have multiple connecting portions, to which each end portion of the stator coils on the side of the end cover is connected, and
 the multiple connecting portions are arranged at intervals in a circumferential direction of the terminal sub-assembly. 
 
     
     
       5. The fuel pump according to  claim 1 , wherein the conductive members have multiple connecting portions, to which each end portion of the stator coils on the side of the end cover is connected by welding, and the multiple connecting portions are arranged in a circumferential direction of the terminal sub-assembly at equal intervals of an angle, which is calculated by dividing 360 degrees by a number of the stator cores. 
     
     
       6. The fuel pump according to  claim 1 , further comprising: a neutral-point sub-assembly, to which each of the other end portions of the stator coils on the side of the pump cover is connected to form a neutral point for the respective phase windings, wherein the neutral-point sub-assembly is provided in the other axial side portion of the stator on the side of the pump cover.